Directional drilling apparatus



Sept 7, 1954 G. B. BETTES DIRECTIONAL DRILLING APPARATUS Filed Aug. 13, 1948 CP-IZ:

Patented Sept. 7, 1954 'DIRECTIONAL DRILLING APPARATUS George B. .-Bettes, Casper, Wyo., `assignor to Eastman @il Well -Survey Company, Denver, Colo., a .corporation of Delaware .Application August 13, 1948, "Serial No. 44,160

(Cl. Z55-1.6)

6 Claims.

'This invention relates to new `and 'useful irnprovements .in directional drilling apparatus.

`In :the .directional drilling .and side-tracking `of bore holes, :it has 'become the :general ipractice to drill a deflected :or 4oilset bore which extends :at van angle from -the'main 'well bore. Because :this deflected bore iis Aof .a smaller diameter than vthe diameter of the :mainwell bore, it zis somettimes diiicultto :follow up `witli a reaming operation. Thedeilected or offset fborexis of a smaller diameter because the .drilling is lperformed v'off -of the face Afof a whipstockor iby means of sa rde- .'iie'ctingtool which lrnustfobviously beundergauge as 'compared ito 'the main well '.bore. lthas ibefcome :the .practice rto Aenlarge the smaller deected 'Joore by zmea'ns Lof :a incarner, 'such `as .any vvof the `well vknown '.pilot .reamers nowin 'general use. .Because ofthe small `diameter of the de- `ii'ected bore, difficulty has Ibeen experienced in :causing the ipilot of the `:reamer to enter .said bore.

:Itis oneobiect of the present invention toupro- -.vide .an 'improved -ldirecti'onal .dri-lling :apparatus which -is so -constru'cted `that reaming out Lof `a previously =iormed deflected bore -of relatively fsmall fdiameter may be -eiciently carried out.

important =object foi ithe invention 'is to provide an improved directional drilling apparatus which includes ctn-elongate pilotfstem or `pipe is combined with `a reaming bit and which functions ito Iacouraltely guide said `reaming bit downwardly Valong the smaller ydiameter deflected bore, whereby emcien't follow up reaniing of said. bore may be `accomplished.

Another object of 'the present invention is tov `7provide anirriproved apparatus,of the i'character' described, 'wherein an elongate pilot element is -detachably .connected with the ire'aming mit `.and is arranged .to .be urged toward fone side of the mali-n'well lbore by means foi fuidpressure, where- Aby :a irota'tionof the` :drill pipe lwill cause 'the .guide Ielement to nnd thedefle'c'ted bore `which has been 'previously Aformed 1and which iis -of -a smaller l'diameter 'than Ethe -main `-well fbore; the detachable connection between theelongate-element-and fthe 'reaming bit permitting 'said bit :to be detached from `said 'element ait-er the latter 4is disposed in 'the deected lbore, whereby 'it subsequently iunc- :tions las -a l`guide -for guiding r'the bit within `Isuch "deflected bore.

A 'still "further 'obj ect o'i" the invention is to` provide an improved 4reami-ng apparatus, of the character described, 'wh-ichis `so constructed 'that when the reaming -bit anddrill pipemove'downwardly along'the-guidestema clearance between 2 the bore of the 'drill pipe Yand said stem` -is `provided to .provide `freecirculation'through the drill pipe and reaming Kbit.

-A particularobject of `the invention is to provide an `improved apparatus, of the character Adescribed, Ywherein the .elongate .guide'or -pilot ele-- ment or stem may be removed :by a .suitable retrieving tool at `any time following' its disconnection with the reaming bit so that a well survey -instrumentor other itoolrnay, if desired, be run downwardly through the `drill pipe tand extend outwardly through the -bit to allow asurvey operation to 'be performed.

The construction v'designed to carry out the invention will be hereinafter described together with other features of Vthe invention.

The invention will be `more readlyunderstood from a. reading 'of the -following'specification and by reference to the accompanying drawing,

'wherein an example of 'the invention fis shown,

and wherein:

Figure -l is'a view of a'well bore 'illustrating the improved apparatus, V'constructed Vin accordance with the invention, lowered within awell bore,

:Figure 2 is asimilar View illustrating the pilot or guide element -oi .the apparatus :moved radially `to one side of 'the well boreby means of .the fluid pressure,

Figure 3 :is `a similar view illustrating `the reaming operation which is performed within the deflected well bore, and

.Figure 4 is an enlarged, transverse, vertical, ysectional View of the flower :portion of vthe drill pipe and the upper portion :of Vtheipilot or :guide element and 'illustrating the .connection therelbetween.

In .the drawings, `the .numeral ID designates la main well bore which has been drilled in the usual manner. A deflected :or vangular well bore I I which has a diametersmaller 'thanthediameter of the main well boreextends from the lower end of said main bore and lis ordinarily disposed `at Aan Vangle there-to, vThe smaller lor deflected `bore I I has been formed lby means of a drill bit which Ihas been deected off of Aa whipstock yor other deflecting tool; it is possibletha't said bore ymay have `been `formed by means of any of lthe well known 'knuckle joint deflecting -toolswhch 'are `in general use.

After the smaller deflected bore 1I'I has been formed, it is necessary that said bore `be reamed to Substantially the same size as the main well bore JI!! and it is for this purpose that the improved yapparatus is designed. This apparatus includes. @the 'usual tubularfdrill pipe I2 which has a reaming bit I3 connected to its lower end. The reaming bit includes the usual cutters I4 and is provided with an axial bore I5 which extends entirely through its shank. The bit shank is externally threaded whereby it may be connected through the usual tool joint I2a with the drill pipe I2.

An elongate tubular pilot or guide element I6 which is illustrated as a section of pipe or tubing I6 has its upper end connected with a sub I'I, the latter having an external diameter which is slightly larger than the external diameter of the element or stem I6, whereby an external, annularshoulder I8 is formed at the upper portion of the guide element or stem. The tubular pilot or guide element I6 is adapted to extend downwardly through the reaming bit I3 and the external shoulder I8 is adapted to engage an annular seat I9 which is formed at the upper end of a removable landing ring 2U which is removably mounted within the bore I5 of the shank of the bit I3. This landing ring has a tight press t in the reaming bit so as to be rotatable with the bit, but may be removed by hammer blows when the bit is disconnected. This disposes the sub I'I within the bore I2b of the tool joint I2a and the lower end of the element I6 extends a considerable distance below the reaming bit I3. The lower end of the pilotl or guide element or stem I6 is closed and spaced slightly above this lower end, a radial port 2I is provided in the wall of said element. Thus, any fluid ilowing downwardly through the tubular element or pipe I6 will be ejected through the relatively small port or orice 2l. The pressure of this ejecting fluid striking the wall of the well bore will tend to urge the lower end of the pilot or guide element in a direction opposite to that side on which the port 2| is located.

The pilot or guide element I6 is arranged to be connected in its seated position to the drill bit I3 by means of a frangible shear pin 22. As is clearly shown in Figure 4, the shear pin extends through the upper portion of the element and has its ends engaged within openings formed in the landing ring 20 press t mounted within the shank of the bit I3. The bore I6a of the pilot or guide element I6 has its upper end communicating with the bore Ila of the upper sub I'I. The bore I'Ia terminates short of the upper end of the sub and is in communication with longitudinal passages 23 which extend from the top of the sub to said bore. A fishing or retrieving neck 24 is preferably formed integral with the upper end of the sub I'I and the longitudinal passages 23 are disposed around the shank of said neck. v A suitable packing ring 25, preferably of the O ring type is mounted on the sub I'I and seals the joint between the exterior of said sub and the bore I2b of the tool joint I2a.

In the operation of the apparatus, the assembly is made up as illustrated in Figures l and 4 with the elongate pilot or guide element or stem I6 extending downwardly a substantial distance below the reaming bit I3. The external shoulder I8 at the upper end of the guide or pilot element is engaged with the seat I9 of the landing ring 20 and the shear pin 22 is connecting the element with the bit, whereby the pilot or guide element may be lowered and raised within the main well bore Ill by means of the drill pipe I2. At this time the sub II at the upper end of the guide element I6 is disposed within the bore |219 of the tool joint I2a and the packing ring 25 forms a seal between said sub and the bore of said J'oint.

The assembly or apparatus is lowered to the bottom of the main well bore and because the guide element is disposed substantially axially of the drill pipe, the lower end of the pilot or guide element will engage the shoulder .A which has been formed between the main well bore and the smaller deflected bore II. Upon reaching this position, a pump pressure is applied through the drill pipe and drilling fluid is pumped downwardly through said drill pipe. This fluid under pressure will flow through the longitudinal passages 23, then through the bore I 'Ia of the sub I1 and finally into the bore Ita of the tubular pilot or guide element I 6. As has been noted the lower end of this element is closed with the result that the fluid under pressure is directed outwardly in a forcible stream through the restricted radial port or passage 2| and the force or pressure of this uid striking the wall of the main well bore I will deflect the lower end of the pilot or guide element into contact with the opposite wall of the well bore. Deflection will readily take place because the tubular pilot is of considerable length, such as ten feet or more. This length permits considerable ilexibility at the lower end of the tube, at least enough to move the few inches to one side of the main bore. In a well where the main bore is, say, 9 inches in diameter, the deiiected bore will be 51/2 or 6 inches. Thus, the end of the tubular pilot need only be moved, at the most, only 31/21 inches to reach the side of the main bore if the pilot is about 2% inches in diameter. There will also be some sloppiness at the frangible pin, but this is not a necessity although it may be of some assistance where the deflection must be greater than noted. The drill pipe I2 is then slowly rotated and a slight downward pressure is applied thereto and it will evident that as soon as the lower end of the pilot or guide element I6 moves opposite the smaller deflected bore II, the pilot or guide element will immediately enter said bore. The drill pipe is then lowered until the lower end of the guide stem or element I6 is engaged with the lower end of the deflected bore II. The weight of the drill pipe is then imposed on the shear pin 22 to fracture or shear said pin and thereby disconnect the reaming bit I3 from the pilot or guide element.

The drill pipe and reaming bit are then moved downwardly with the pilot or guide element I6 remaining stationary because of its engagement with the lower end of the deflected bore II. Upon reaching the shoulder A, the drill pipe is rotated to rotate the bit I3 and thereby ream out the smaller deflected bore II to substantially full gauge or the same size as the main well bore I0. It will be evident that during the reaming operation, the pilot or guide element functions to guide the reaming bit throughout the length of the smaller deflected bore. It is also pointed out that as the drill bit and drill pipe move downwardly with respect to the pilot or guide element and its connected sub II, the sub moves upwardly into the drill pipe which has a slightly larger bore than the bore of the tool joint I2a. This means that the drilling iluid which is circulated downwardly through the drill pipe may freely by-pass the sub I'I and may also by-pass around the exterior of the tubular pilot or guide element I6, whereby there is substantially no obstruction to the necessary drilling fluid must be circulated during the reaming operation.

After the smaller deflected bore II has been drilled out to full size, as shown in Figure 3, it may be desirable to obtain a survey of the de- :einsame -ecte here :to :determine =or @heck its directmn and 'inclination :such survey iis desirable :or mecessary,:asuitaiiletretrlieyingfnri'fisning todlimot ."slioum) :is lowered ithrongh ithe well A:pipe fand tis engaged wwith kthe lretrieving or zsliing nenk 22d :and fthe rent'ire :pilot :or guide :element L5 :is Fre- -trieved through the airill pipe. 'The pipe :and :bit :are ithen zraised slightly `ol bottom 'and ,a :suitable iwell surveying instrument :may 'he dropped for .loweredfthroughitheidrill pipe `seas :to extend aout- -rwardlyjbelow the` .Teaming :hit ilt is noted itliat :the shoulder :IB ron ithe landing .ring `,'20 ipro- 1-vlides ia :support for such instrument. En tins ,rmanner a survey rof :the inclination and :deviation lof ftheideflected lbore:may :be iaccomplished before Lthe -drill pipe :andreaming :bit areremoved. The -fsurvey iinstrument may be recovered feit-her #with lthe drill pipeaoraby meansfvofaafwire line :or cable, :as-desired.

If itfis not desired to r.obtain gaisurivey, the Ypilot :and iguide :element L6 will be :removed when the drill A,pipe rand rea-ming -bit fare ebrought to the surface. -From Ythe .foregoing it .will be seen #that a simple and efficient apparatus for reaming a smaller .diameter :deflected iboreis provided. The elongate pilot -or -guide lstem or element I6 is normally attached to the drill pipe so as to be lowered therewith through the main well bore. YUpon rreaching bottom, the pressure fluid which Alis 'pumped downwardly through the drill pipe `is `utilized to fdeflect the lower enlof the pilot Jele- 1mentlinto ia position where it will readily enter Ithe deflected -bore -I-I. Upon its `entry into said bore, the pilot element is readily detached from the drill pipe, whereby the drill pipe and its reaming bit may move downwardly with reference to said element. During the reaming operation, the pilot or guide element forms an axial guide to assure that the reamer will follow the deflected bore Il. The pilot or guide element may be retrieved either with the drill pipe when the latter is removed or may be recovered and brought to the surface by means of any well known retrieving or fishing tool. The

vremovability of the pilot element independently of the drill pipe makes it possible to accomplish a well surveying operation before the drill pipe and reaming bit are brought to the surface.

The foregoing description of the invention is explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made, within the scope of the appended claims, without departing from the spirit of the invention.

What I claim and desire to secure by Letters Patent is:

l. A` drilling apparatus including, a drill pipe adapted to be lowered within a well bore, a reaming bit having an axial bore secured to the lower end of the drill pipe, an annular support Within the drill pipe, a tubular pilot element extending through the drill bit and projecting a substantial distance therebelow, the upper end of said element being enlarged and supported upon the support within the drill pipe, whereby said element cannot pass completely through the pipe and bit in a downward direction, and releasable means normally securing the element to the drill pipe and bit so that the element may be lowered therewith, said element comprising a tubular conductor having a radial port in its lower portion and having its lower end closed, whereby pressure fluid pumped downwardly through the drill pipe and conductor will be ejected outwardly through said port and will function to fdefledt :said fconductor 'radially against dihewwall zof .the 'well bore so fthat subsequent 4notationfoil? `th'e @drill pi-pe, #bit .and fconductor `.will irritate .the -shower rend 4of the conductor ia :path adjacent l'the iurall rof 'the bore.

1A drilling :apparatus including, :a drill .pipe zadapted'fto ibelowered lwithin faavell bore, r arream. ling .mit having 1an .axial 'bore :secured to the :lower remi auf ithe drill pipe, an annular support Within the drill ipipe, 'a itubular pilnt :element extending ith'rough the drill bit and proectingiasubstantial distance therebelow, :the :upper end .of -said ele- :ment-,being:enlargedmdsupportednponlthezsupport 'mithm fthe fdrill pipe, whereby said 'element annot ,pass completely ymtfkroug'h "theipipeyand ibit :a downward rdreo'tion, releasable lmeans nor- 4irnally'fsecx-iring :the element ito the fdrill pipe yand bi-t rso that theelementJmaybeiloweredtherewth, said elementfcomprisinga tubular :conductor .havfingza radial pontiin itsloweriportionzan'd .'hayingits flower gend closed, whereby zpressu-re ln'id zpumped downwardly through the :drill lpipe fand iconduc 'tor twill the ejected outwardly 'through .said .port 5and will :function `:to :deect said =conductor radi- ;allyzagainst 'the wall of 'the well nboraso :thatsubl:sequent :rotation-.o tthe :drill pipe, .bit 'and :conduc- :tor rotate the lower endfof thenonductorina math .adjacent the `iwal] of the rbore, zdetachmem'. :of the lreleasable 4means rpermitting downward .movement :of *the pipe tand brit with :respect toitheiconductorpwherebyfsaid bit'is guided aby the iconductorr:duringiazreamingfoperationandimeans for circulating La sdrilling :fluid downwardly through the drill pipe and around the exterior of the pilot conductor during the reaming operation.

3. A drilling apparatus as set forth in claim 1, wherein the releasable means connecting the pilot element with the drill bit is a shear lpin which may be fractured when the pilot element is engaging the lower end of the bore and the weight of the drill pipe is imposed thereon.

4. A drilling apparatus including, a drill pipe adapted to be lowered within a well bore, a reaming bit having an axial bore secured to the lower end of the drill pipe, an annular support within the drill pipe, a tubular pilot element extending through the drill bit and projecting a substantial distance therebelow, the upper end of said element being enlarged and supported upon the support within the drill pipe, whereby said element cannot pass completely through the pipe and bit in a downward direction, releasable means normally securing the element to the drill pipe and bit so that the element may be lowered there with, means for deflecting the lower end of the pilot element radially into engagement with one side of the well bore, whereby rotation of the drill pipe and bit with the element attached thereto rotates the lower end of the element in a path adjacent the wall of said bore, and means on the upper portion of the pilot element adapted to be engaged by a retrieving tool, whereby when the connecting means between the element and drill pipe and bit is detached, said element may have a line connected therewith by a retrieving tool and be removed from the well bore independently of the drill pipe and bit.

5. A drilling apparatus attachable to the lower end of a drill pipe for enlarging an earth bore smaller than a main earth well bore and which has been drilled ofi therefrom at an anglel said apparatus comprising a -reaming bit having an axial bore and being of a size to drill a bore of greater diameter than the said small bore, means securing the bit to the lower end of the drill pipe, an elongated pilot element extending through the bit bore and having its lower end projecting below the bit a substantial distance and being of a size to be received in the smaller bore, means comprising a frangible element for securing the upper end of the pilot element to said bit whereby the element may be lowered with the drill pipe and bit and caused to extend into the smaller bore an appreciable distance and when so positioned permitting the element to be detached from the fbit by application of weight of the drill pipe suilicient to shear the frangible means and thereby allow for movement of the bit and pipe with respect to said pilot element so that the bit when rotated can be' guided by the 'portion of the element in the smaller bore and enlarge said smaller bore without any appreciable change in its direction, and means for causing the lower end of pilot element when it is in the main bore to assume a position where it can enter the smaller bore when the drill pipe is rotated.

6. A drilling apparatus attachable to the lower end of a drill pipe for enlarging an earth bore smaller than `a main earth well bore and which has been drilled off therefrom at an angle, said apparatus comprising a reaming lbit having an axial bore and being of a size to drill a, bore of greater diameter than t'he said small bore, means securing the bit to the lower end of the drill pipe, an elongated pilot element extending through the bit boreand having its lower end projecting below the bit a substantial distance and being of a size to be received in the smaller bore, means vfor releasably securing the upper end of the pilot element to said bit, said releasable means being of a type maintaining the element connected to the bit so the element may be lowered with the drill pipe and bit and caused to extend into the smaller bore an appreciable distance and when so positioned permitting the element to be released from the bit by such manipulation of the drill pipe as to allow for downward movement of the bit and pipe with respect to said element so that the bit when rotated can be guided by the portion of the element in the smaller bore and enlarge `said smaller bore without any appreciable change in its direction, and means for deflecting the lower end of the pilot element when it is in the main bore so it can be caused to enter the smaller bore and then be subsequently released, said last named means comprising a conduit through the element from its upper end toward the lower end With a radial port whereby uid pumped down the drill pipe can be laterally discharged from the radial port and thereby deilect the element.

References Cited in the i'lle of this patent UNITED STATES PATENTS Number Name Date 1,859,490 Atkinson May 24, 1932 1,941,723 Stroud Jan. 2, 1934 2,167,194 Anderson July 25, 1939 2,227,233 Scott et al Dec. 31, 1940 2,405,717 Schadel Aug. 13, 1946 

